Amy was reading a book I came in.
A. when B. while C. because D. though
Amy was reading a book I came in.
A. when B. while C. because D. though
A
【解析】考查时间状语从句的引导词。because“因为”；though“尽管；虽然”，与句意不符，可排除；while 引导的时间状语从句通常用进行时态，表示主句的动作发生的同时，从句的动作也正在发生，when“当……的时候”，常用来引导时间状语从句，根据句意，所以选择答案A。